Re: [Qemu-devel] S390 bios breaks in qemu 2.10.rc3

[Cornelia Huck <cohuck@redhat.com>]

On Thu, 24 Aug 2017 20:14:06 +0200
Christian Borntraeger <borntraeger@de.ibm.com> wrote:

> On 08/24/2017 07:38 PM, Farhan Ali wrote:
> > 
> > 
> > On 08/24/2017 12:07 PM, Peter Maydell wrote:  
> >> On 24 August 2017 at 16:53, Farhan Ali <alifm@linux.vnet.ibm.com> wrote:  
> >>>
> >>>
> >>> On 08/24/2017 11:50 AM, Thomas Huth wrote:  
> >>>> True, so that could still be an issue. Looking at the cio.h in the
> >>>> kernel, they define the struct like this:
> >>>>
> >>>> struct ccw1 {
> >>>>         __u8  cmd_code;
> >>>>         __u8  flags;
> >>>>         __u16 count;
> >>>>         __u32 cda;
> >>>> } __attribute__ ((packed,aligned(8)));
> >>>>
> >>>> So I guess adding the aligned(8) is the right way to go?  
> >>  
> >>> This was my initial fix and it works on my system. But for some reason this
> >>> fix does not work on my colleague's system. So I am hesitant about
> >>> submitting this fix  
> >>
> >> It seems like it ought to be the obvious fix, so I would double
> >> check that on your colleague's system the change really did
> >> get recompiled and it's actually using the new version (that
> >> sort of mistake can be easy to make and very confusing...)  
> 
> >>
> >> thanks
> >> -- PMM
> >>  
> > 
> > So after trying again with the fix, it seems to work on my colleague's system for most cases. It fails for LDL DASD boot case.... we are still investigating it.  
> 
> So chances are that this is an independent problem, I guess?
> 

OK, to recap:

- the current pre-built bios seems fine
- rebuilding the bios may yield a version that fails on some systems
  (different compiler?)
- adding aligned(8) looks like the right thing to do
- it seems to fix the problem, but on at least one system something
  still seems off (under investigation)